This invention relates to a process for the production of a washing additive containing active ingredients for improving the removability by washing of bleachable stains, fatty or oily stains and pigment-containing soil, the washing additive being obtained in the form of a tablet in its production by the process according to the invention. When added to a wash liquor containing a standard detergent containing a per compound, the use of the tablets improve the removal of fatty/oily stains, pigment-containing soil and bleachable stains from the laundry.
Washing additives in tablet form have long been known as wash-active ingredients, they often contain a bleach activator for per compounds either on its own or in combination with other active ingredients and standard tabletting aids. One such product is described, for example, in Great Britain Pat. No. 1,423,536. In conjunction with the per compounds normally present in modern universal detergents, bleach activators improve the removal of bleachable stains. Although, in general, the detergents also contain bleach activators in addition to per compounds, difficulties frequently arise during the storage of detergents containing both per compounds and activators as a result of the fact that the bleach activator acts prematurely on the per compounds so that the per compounds lose some of their effectiveness. In the washing of heavily soiled clothing, such as working clothes for example, importance is attached not only to the satisfactory removal of bleachable stains, but also to the removal of fatty or oily stains and pigment-containing soil. Accordingly, washing additives which, in addition to a bleach activator, also contain nonionic surface-active compounds (or tensides), certain quaternary ammonium compounds to boost detergency and, optionally, organic phosphonic acid derivatives have also been described with a view to improving the removal of the various types of stains mentioned above (cf. DE-OS No. 28 57 153). This German published application relates to washing additives in which the above-mentioned combination of active ingredients is applied to a flexible carrier. For washing, the carrier charged with active ingredients is introduced with the laundry into the washing machine where it develops its effect during the washing process. On completion of washing, the flexible carrier for the active ingredients remains in the laundry and has to be separated therefrom.
Washing additives in tablet form are frequently sensitive to mechanical stressing and crumble before using or do not dissolve completely or quickly enough if the composition and production of the tablets are designed to provide the tablets with adequate mechanical stability.